Traditionally when concrete, or other similar formable or settable material, is used to form stairs, a mould is made for the exact form of the flight of stairs required. Concrete is then poured into the mould. The concrete is then allowed to set and the resulting flight of stairs is removed from the mould.
This is an expensive method of forming stairs, as for each different flight of stairs a new mould is required.
There has therefore been a long felt want for a product that will allow numerous different stair shapes to be formed without needing to invest in numerous different moulds.
Typically moulds have been made from wood to keep the cost down. In moulding environments wood has a limited life. It eventually breaks down from wear and tear, requiring a new mould to then be made.
U.S. Pat. No. 5,133,530 discloses a stair forming apparatus. A key short coming of U.S. Pat. No. 5,133,530 is its inability to adjust the nosing of the stairs. The nosing is the distance of the overlap of two adjacent stairs treads. US '530 specifically states that the invention can only produce a right angle stair profile. In many countries, regulations and rules for stair designs govern the maximum and minimum lengths of the treads, risers and nosing for any particular stair type eg. public access, main private stairways etc. The ability to extend the actual tread length by adding a nosing is very helpful to architects and designers when limited room is available.
In addition the individual units in U.S. Pat. No. 5,133,530 must all be set at the same unit pitch, there is no ability to vary the pitch between units, only globally of all the units. This also increases the difficulty of adding and removing units to form more or less stairs. The mechanism used in their apparatus also increases the cost of the apparatus and makes it less portable.
It is therefore an object of the present invention to provide a stair forming apparatus and/or related methods that at least overcomes some of the problems of the prior art, or to at least address the above desiderata, or at least provide the public with a useful choice.
In this specification if and where reference has been made to patent specifications, other external documents, or other sources of information, this is generally for the purpose of providing a context for discussing the features of the invention. Unless specifically stated otherwise, reference to such external documents is not to be construed as an admission that such documents, or such sources of information, in any jurisdiction, are prior art, or form part of the common general knowledge in the art.